Most dogs enjoy chewing on things although preferences vary as to the hardness of the substances favored. Some dogs like to chew on very hard materials such as cow bones, wood, nylon, or polyurethane, others prefer softer chews such as rawhide, while still others favor freeze dried snacks. Some dogs, due to their age, may not be able to chew on the hard substances. Young dogs have insufficiently developed teeth, while old dogs may have diseased gums or may have lost some of their teeth.
In appreciation of this problem, there has been previously developed an edible dog chew that is digestible and nutritious along with a texture or hardness which is individually adjustable by the application of heat to suit a wide variety of dog's preferences or needs. Such dog chews utilize a mixture containing primarily casein and are disclosed in U.S. Pat. Nos. 5,200,212 and 5,240,720, which are assigned to T.F.H. Publications, Inc. Other wholly digestible, edible dog chews have also been developed that are formed largely from various starch products.
In U.S. Pat. No. 5,827,565 owned by T.F.H. Publications Inc. and included herein by reference, there is disclosed a process for making a heat expandable dog chew comprised primarily of injection molding potato starch granules and an attractant. Attractants recited include chicken powder, liver powder, ham, turkey, beef and or fish. Natural vegetable additives such as spinach or carrots also may be added. The resultant mixture is molded under heat and pressure into a desired form, such as a dog bone. The dog bone so produced may be modified in texture or hardness by subsequent heating, preferably in a microwave oven.
In U.S. Pat. No. 6,126,978, which is a continuation-in-part of U.S. Pat. No. 5,827,565, and which is owned by T.F.H. Publications Inc. and included herein by reference, there is disclosed a dog chew having natural fruit flavor to increase the dog's appetite for such chew. The chew may be formed by extruding a mixture of potato starch, water and calcium carbonate to form granules adding a fruit flavor to the granules and injection molding such ingredients into the shape of a dog chew. Such a fruit flavored dog chew may also include natural food coloring to enhance the attractiveness of the chew to the dog owner. The food coloring may also correspond to the fruit flavor, and the dog chew disclosed therein may also embody a breath sweetener for a dog such as mint, spearmint, peppermint or wintergreen and may also include parsley. The preferred form of such edible chew maintains the basic ingredient of a heat-expandable starch, such as potato starch. Fruit flavoring may be added to the granules of a mixture of potato starch, water and calcium carbonate along with natural fruit flavorings.
In U.S. Pat. No. 6,200,616, which is a continuation-in-part of U.S. Pat. No. 6,126,978, owned by T.F.H. Publications and included herein by reference, there is disclosed a method of forming an animal chew by supplying substantially dehydrated fruit chips and a food coloring, forming a mixture of the two and injection molding or compression molding the mixture to form an animal chew. In a second embodiment, the fruit chips may be mixed into a polyurethane resin and formed into a shape.
In U.S. Pat. No. 6,159,516, which is owned by T.F.H. Publications, Inc. and included herein by reference, there is disclosed a process for forming starch into a molded article by combining starch and water to form a mixture, heating the mixture in a vented barrel extruder, forming beads having a given water content and injection molding the beads to form a molded article.
Attention is also directed to the following United States patents, owned by T.F.H. Publications Inc.: U.S. Pat. No. 5,476,069 entitled “Molded Rawhide Chew Toy”; U.S. Pat. No. 6,093,427 entitled “Vegetable Based Dog Chew”; U.S. Pat. No. 5,827,565 entitled “Edible Dog Chew”; U.S. Pat. No. 5,941,197 entitled “Carrot-Based Dog Chew”; U.S. Pat. No. 6,180,161 entitled “Heat Modifiable Edible Dog Chew”; U.S. Pat. No. 6,126,978 entitled “Improved Edible Dog Chew”; U.S. Pat. No. 6,110,521 entitled “Wheat & Casein Dow Chew With Modifiable Texture”; U.S. Pat. No. 6,093,441 entitled “Heat Modifiable Peanut Dog Chew”; U.S. Pat. No. 4,093,427 entitled “Vegetable Based Dog Chew”; and U.S. Pat. No. 4,093,427 entitled “Heat Modifiable Edible Dog Chew” No. 6,180,161. In addition to such patents, attention is also directed to the art cited in said patents, as such art may relate to the field of molded edible pet products.
U.S. patent application Ser. No. 11/372,992 filed Mar. 10, 2006, is directed at animal chews comprising more than one material wherein the materials may be different in, for instance, hardness, flexural modulus, tensile strength or clarity and is incorporated herein by reference in its entirety. The materials may be disposed in layered relationship. The chews may be formed by insert molding, multiple component molding, rotary molding, shuttle molding or any number of melt conversion processes.
Additionally, while the above prior art confirms numerous successful efforts to provide an edible chew, there remains, of course, a continuing need to develop other techniques of manufacture that will provide expanded and more efficient production capability, particularly for multi-component edible chews or treats.